donation. 1  an act or instance of presenting something as a gift, grant, or contribution. 2  a gift, as to a fund; contribution.
A black or brown tongue typically is due to the overgrowth of bacteria that normally are present on the tongue. This, too, can be caused by the killing of some bacteria with antibiotics so other bacteria overgrow. But the most common cause of discoloration of the tongue is the overgrowth of a fungus. The most common fungus is called candida. But overgrowth of the candida fungus turns the tongue white. Infection with candida is called candidiasis, and when it happens on the tongue the condition is called thrush.
The most obvious sign of a black tongue is discoloration of the tissue on the tongue. Basically, this occurs when the papillae (small raised portions) of the tongue elongate for some reason and accumulate material. The collected matter in the tongue usually produces a dark appearance, but âblack tongueâ could also lead to a white, green, brown, or tan appearance, depending on the root cause. Your tissue may also take on a textured, âhairyâ feeling.